I have several cases where it would be useful to be able to have an interactive webpage as part of a tool. They are basically interactive filtering operations; for example:

to select a subset of items from a current dataset using checkboxes (e.g. a set of rows from some tab-delimited data)

pick one or more files to load from a remote file system

This functionality would be easy to implement as a CGI, but I'm not sure how (or if!) it could be done as a Galaxy tool. I thought perhaps as a visualisation option, but any ideas would be appreciated!